July 2006doc.: IEEE 802.11-06/0920r1

IEEE P802.11
Wireless LANs

Compressed Steering Matrices Order
Date: 2006-07-07
Author(s):
Name / Company / Address / Phone / email
AssafKasher / Intel / POB 1659, Haifa 31015, Israel / 97248651547 /
Gal Basson / Intel / POB 1659, Haifa 31015, Israel / 972547885404 /
Joonsuk Kim / Broadcom / 190 Mathilda place, Sunnyvale, CA94086 / 1-408-543-3455 /
Vinko Erceg / Broadcom / 15435 Innovation Dr.
San Diego, CA92128 / 1-858-521-5885 /


This submission addresses a comment referring to the fact that the order of the steering matrices feedback (by frequency and then by element) is different from the order of matrix sending in other sections (all the elements in one matrix and then the elements of the matrix in the next frequency).

Replace the following paragraphs in page 73, section 7.4.7.8 (Compressed Steering Matrices Feedback frame)

QuantizedCSI Feedback Information field is defined as: Data: Channel matrix elements indexed in order by data subcarrier index and angle. This simplifies the interpolation angles between subcarriers, if grouping other than 1 is employed. The explanation on how these angles are generated from the steering matrix V is given in 20.3.5.2.3

The angles are sent in order according to Table n46.

with

QuantizedCSI Feedback Information field is defined as: Channel matrix elements indexed in order by matrix angles as shown in table n46 and data subcarrier index. The explanation on how these angles are generated from the steering matrix V is given in 20.3.5.2.3. The order of the elements in this field is explained by this pseudo code:

QuantizedCSI Feedback Information field contains the channel matrix elements indexed first by matrix angles in the order shown in table n46 and secondly by data subcarrier index from smallest frequency to highest frequency. The explanation on how these angles are generated from the steering matrix V is given in 20.3.5.2.3. The order of the elements in this field is explained by this pseudo code:

The angles in a compressed steering matrix per tone are sent in order according to Table n46.

Replace the two examples in page 75, end of section 7.4.7.8 (Compressed Steering Matrices Feedback frame)

Example: 2x2, 20MHz, no grouping, bits for each  = 3, bits for each =5. Each ij over all tone indices has 168 bits. Each ij over all tone indices has 280 bits.

bits / b1..b5 / b6..b10 / … / b276..b280 / b281..b283 / b284..b286 / … / b446..b448
data / 11(f-28) / 11(f-27) / … / 11(f28) / 21(f-28) / 21(f-27) / … / 21(f28)

Example: 4x2, 40MHz, 4 tone grouping, ,  = 4. Each ij over all tone indices has 120 bits. Each ij over all tone indices has 60 bits.

bits / b1..b4 / b5..b8 / … / b117..b120 / b121..b124 / … / b361..b362 / … / b661..b664 / … / b899..b900
data / 11(f-58) / 11(f-54) / … / 11(f58) / 21(f-58) / … / 21(f-58) / … / 32(f-58) / … / 42(f58)

with

Figure n28 – Example of bit ordering for angles for 2x2 V with b= 3, b= 5, no grouping for 20MHz, where the matrix V per tone is encoded in 8 bits.

bits / b1..b5 / b6..b8 / b9..b13 / b14..b16 / … / b441..b445 / b446..b448
data / 11(f-28) / 21(f--28) / 11(f-27) / 21(f--27) / … / 11(f28) / 21(f28)

Figure n29 – Example of bit ordering for angles for 4x2 V with b= 2, b= 4, 4 tone grouping for 40MHz, where the matrix V per tone is encoded in 30 bits.

bits / b1..b4 / b5..b8 / … / b27..b28 / b29..b30 / b31..b34 / … / b59..b60 / … / b871..b874 / … / b899..b900
data / 11(f-58) / 21(f-58) / … / 32(f-58) / 42(f-58) / 11(f-54) / … / 42(f-54) / … / 11(f58) / … / 42(f58)

Submissionpage 1Assaf Kasher et al, Intel.